Abstract

Photosynthetic responses to various temperature and PAR conditions of two carrageenophytes, Eucheuma denticulatum and Kappaphycus striatus (so-called Sacol strain), cultured in shallow areas of Bali, Indonesia, were examined using dissolved oxygen measurements and pulse–amplitude-modulated (PAM) fluorometry. Net photosynthesis–irradiance (P–E) curves at 26 °C revealed that the values of Pmax for E. denticulatum and K. striatus were 13.76 and 5.02 μg O2 gfw−1 min−1 (12.38–15.12 and 4.55–5.50 μg O2 gfw−1 min−1, 95 % Bayesian prediction interval (BPI)), respectively. Photoinhibition was not observed even at 1000 μmol photons m−2 s−1. Gross photosynthesis and respiration characteristics over a range of temperatures (8–36 °C) revealed optimum temperature for photosynthesis to be 31.1 °C for E. denticulatum, and 31.6 °C for K. striatus. These characteristics of photosynthesis indicate that both farmed seaweeds are well adapted to the light and temperature conditions of the cultivation site. However, studies on longer timescales for photochemical efficiency, photosynthesis, and respiration are still needed to determine their limits of tolerance. We also hypothesize that higher values of photosynthetic parameters for E. denticulatum suggest that this species is relatively superior in productivity under optimal conditions, conditional on the farming method.

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Acknowledgments

This research was sponsored in part by a CREST (no. JAJJ110062) from Japan Science and Technology Agency (SK) and Grant-in-Aid for Scientific Research (nos. 25340012, 25450260, and 16H02939) from the Japanese Ministry of Education, Culture, Sport, and Technology (RT and GNN). All authors have provided consent. This research was part of the dissertation submitted by the first author in partial fulfillment of the PhD degree.

Luhan MRJ, Sollesta H (2010) Growing the reproductive cells (carpospores) of the seaweed, Kappaphycus striatum, in the laboratory until outplanting in the field and maturation to tetrasporophyte. J Appl Phycol 22:579–585CrossRefGoogle Scholar

Luxton DM (1993) Aspects of the farming and processing of Kappaphycus and Eucheuma in Indonesia. Hydrobiologia 260/261:365–371CrossRefGoogle Scholar